/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.crazymaker.servlet.container.netty.resource;


import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

public abstract class AbstractArchiveResourceSet extends AbstractResourceSet
{

    private URL baseUrl;
    private String baseUrlString;

    private JarFile archive = null;
    protected HashMap<String, JarEntry> archiveEntries = null;
    protected final Object archiveLock = new Object();
    private long archiveUseCount = 0;


    protected final void setBaseUrl(URL baseUrl)
    {
        this.baseUrl = baseUrl;
        if (baseUrl == null)
        {
            this.baseUrlString = null;
        } else
        {
            this.baseUrlString = baseUrl.toString();
        }
    }

    @Override
    public final URL getBaseUrl()
    {
        return baseUrl;
    }

    protected final String getBaseUrlString()
    {
        return baseUrlString;
    }


    @Override
    public final String[] list(String path)
    {
        checkPath(path);
        String webAppMount = getWebAppMount();

        ArrayList<String> result = new ArrayList<>();
        if (path.startsWith(webAppMount))
        {
            String pathInJar =
                    getInternalPath() + path.substring(webAppMount.length());
            // Always strip off the leading '/' to get the JAR path
            if (pathInJar.length() > 0 && pathInJar.charAt(0) == '/')
            {
                pathInJar = pathInJar.substring(1);
            }
            for (String name : getArchiveEntries(false).keySet())
            {
                if (name.length() > pathInJar.length() &&
                        name.startsWith(pathInJar))
                {
                    if (name.charAt(name.length() - 1) == '/')
                    {
                        name = name.substring(
                                pathInJar.length(), name.length() - 1);
                    } else
                    {
                        name = name.substring(pathInJar.length());
                    }
                    if (name.length() == 0)
                    {
                        continue;
                    }
                    if (name.charAt(0) == '/')
                    {
                        name = name.substring(1);
                    }
                    if (name.length() > 0 && name.lastIndexOf('/') == -1)
                    {
                        result.add(name);
                    }
                }
            }
        } else
        {
            if (!path.endsWith("/"))
            {
                path = path + "/";
            }
            if (webAppMount.startsWith(path))
            {
                int i = webAppMount.indexOf('/', path.length());
                if (i == -1)
                {
                    return new String[]{webAppMount.substring(path.length())};
                } else
                {
                    return new String[]{
                            webAppMount.substring(path.length(), i)};
                }
            }
        }
        return result.toArray(new String[result.size()]);
    }

    @Override
    public final Set<String> listWebAppPaths(String path)
    {
        checkPath(path);
        String webAppMount = getWebAppMount();

        ResourceSet<String> result = new ResourceSet<>();
        if (path.startsWith(webAppMount))
        {
            String pathInJar =
                    getInternalPath() + path.substring(webAppMount.length());
            // Always strip off the leading '/' to get the JAR path and make
            // sure it ends in '/'
            if (pathInJar.length() > 0)
            {
                if (pathInJar.charAt(pathInJar.length() - 1) != '/')
                {
                    pathInJar = pathInJar.substring(1) + '/';
                }
                if (pathInJar.charAt(0) == '/')
                {
                    pathInJar = pathInJar.substring(1);
                }
            }

            for (String name : getArchiveEntries(false).keySet())
            {
                if (name.length() > pathInJar.length() && name.startsWith(pathInJar))
                {
                    int nextSlash = name.indexOf('/', pathInJar.length());
                    if (nextSlash != -1 && nextSlash != name.length() - 1)
                    {
                        name = name.substring(0, nextSlash + 1);
                    }
                    result.add(webAppMount + '/' + name.substring(getInternalPath().length()));
                }
            }
        } else
        {
            if (!path.endsWith("/"))
            {
                path = path + "/";
            }
            if (webAppMount.startsWith(path))
            {
                int i = webAppMount.indexOf('/', path.length());
                if (i == -1)
                {
                    result.add(webAppMount + "/");
                } else
                {
                    result.add(webAppMount.substring(0, i + 1));
                }
            }
        }
        result.setLocked(true);
        return result;
    }


    /**
     * Obtain the map of entries in the archive. May return null in which case
     * {@link #getArchiveEntry(String)} should be used.
     *
     * @param single Is this request being make to support a single lookup? If
     *               false, a map will always be returned. If true,
     *               implementations may use this as a hint in determining the
     *               optimum way to respond.
     * @return The archives entries mapped to their names or null if
     * {@link #getArchiveEntry(String)} should be used.
     */
    protected abstract HashMap<String, JarEntry> getArchiveEntries(boolean single);


    /**
     * Obtain a single entry from the archive. For performance reasons,
     * {@link #getArchiveEntries(boolean)} should always be called first and the
     * archive entry looked up in the map if one is returned. Only if that call
     * returns null should this method be used.
     *
     * @param pathInArchive The path in the archive of the entry required
     * @return The specified archive entry or null if it does not exist
     */
    protected abstract JarEntry getArchiveEntry(String pathInArchive);

    @Override
    public final boolean mkdir(String path)
    {
        checkPath(path);

        return false;
    }

    @Override
    public final boolean write(String path, InputStream is, boolean overwrite)
    {
        checkPath(path);

        if (is == null)
        {
            throw new NullPointerException("dirResourceSet.writeNpe");
        }

        return false;
    }

    @Override
    public final WebResource getResource(String path)
    {
        checkPath(path);
        String webAppMount = getWebAppMount();
        WebResourceRoot root = getRoot();

        /*
         * Implementation notes
         *
         * The path parameter passed into this method always starts with '/'.
         *
         * The path parameter passed into this method may or may not end with a
         * '/'. JarFile.getEntry() will return a matching directory entry
         * whether or not the name ends in a '/'. However, if the entry is
         * requested without the '/' subsequent calls to JarEntry.isDirectory()
         * will return false.
         *
         * Paths in JARs never start with '/'. Leading '/' need to be removed
         * before any JarFile.getEntry() call.
         */

        // If the JAR has been mounted below the web application root, return
        // an empty resource for requests outside of the mount point.

        if (path.startsWith(webAppMount))
        {
            String pathInJar = getInternalPath() + path.substring(
                    webAppMount.length(), path.length());
            // Always strip off the leading '/' to get the JAR path
            if (pathInJar.length() > 0 && pathInJar.charAt(0) == '/')
            {
                pathInJar = pathInJar.substring(1);
            }
            if (pathInJar.equals(""))
            {
                // Special case
                // This is a directory resource so the path must end with /
                if (!path.endsWith("/"))
                {
                    path = path + "/";
                }
                return new JarResourceRoot(root, new File(getBase()),
                        baseUrlString, path);
            } else
            {
                JarEntry jarEntry = null;
                if (isMultiRelease())
                {
                    // Calls JarFile.getJarEntry() which is multi-release aware
                    jarEntry = getArchiveEntry(pathInJar);
                } else
                {
                    Map<String, JarEntry> jarEntries = getArchiveEntries(true);
                    if (!(pathInJar.charAt(pathInJar.length() - 1) == '/'))
                    {
                        if (jarEntries == null)
                        {
                            jarEntry = getArchiveEntry(pathInJar + '/');
                        } else
                        {
                            jarEntry = jarEntries.get(pathInJar + '/');
                        }
                        if (jarEntry != null)
                        {
                            path = path + '/';
                        }
                    }
                    if (jarEntry == null)
                    {
                        if (jarEntries == null)
                        {
                            jarEntry = getArchiveEntry(pathInJar);
                        } else
                        {
                            jarEntry = jarEntries.get(pathInJar);
                        }
                    }
                }
                if (jarEntry == null)
                {
                    return new EmptyResource(root, path);
                } else
                {
                    return createArchiveResource(jarEntry, path, getManifest());
                }
            }
        } else
        {
            return new EmptyResource(root, path);
        }
    }

    protected abstract boolean isMultiRelease();

    protected abstract WebResource createArchiveResource(JarEntry jarEntry,
                                                         String webAppPath, Manifest manifest);

    @Override
    public final boolean isReadOnly()
    {
        return true;
    }

    @Override
    public void setReadOnly(boolean readOnly)
    {
        if (readOnly)
        {
            // This is the hard-coded default - ignore the call
            return;
        }

        throw new IllegalArgumentException(
                "abstractArchiveResourceSet.setReadOnlyFalse");
    }

    protected JarFile openJarFile() throws IOException
    {
        synchronized (archiveLock)
        {
            if (archive == null)
            {
                archive = JreCompat.getInstance().jarFileNewInstance(getBase());
            }
            archiveUseCount++;
            return archive;
        }
    }

    protected void closeJarFile()
    {
        synchronized (archiveLock)
        {
            archiveUseCount--;
        }
    }

    @Override
    public void gc()
    {
        synchronized (archiveLock)
        {
            if (archive != null && archiveUseCount == 0)
            {
                try
                {
                    archive.close();
                } catch (IOException e)
                {
                    // Log at least WARN
                }
                archive = null;
                archiveEntries = null;
            }
        }
    }
}
